Radio apparatus



Dec. 29, 1931. J, KERRIGAN 1,838,264

RADIO APPARATUS Filed June 27, 1929 2o ..15 J6 J5 32 s.

INVENTOR 5.71 /f/-z' an,

, ATTORNEY back-lash is prevented iromdeveloping.

Patented Dec, 2Q, ldt

stares PATENT @FFEQE 50H23' KEERIGAN, 0F SPRINGFEZD, MIASSACHIUSETTS,SSIGNOR T0 WESTING'HOUSE MESTRE@ da MMUFAOTUEING CUMPANY, A. CORPORATION0F PENNSYLVANIA BABE@ APPARATUS Application died June Si?,

My invention relates to radio apparatus and it has particular relationtoy controldevicesA for the'tuning reactors comprised in radio receivingsets.

lin the construction of modern radio receivingV sets, it has been foundexpedient to abandon the former custom oi mounting the indicating dialsof the tuning reactors eXteriorlyof the cabinet containing the recei'ving apparatus and, instead, t0 so dispose the dials rearwardly ofthe front panel of the cabinet that minor portions thereof are visiblethrough openings in that anel. it is also novv customary, as exempliiedby a receiving set known as Radiola 17, sold by theltadio vCorporationof America, to associate a yplurality of tuning reactors with a singleindicating dial of the type referred to and, in addition, to provide asingle, eltteriorly disposed, adjusting device that is connected, by aphosphor-bronze cable or the like, to a shaft common to' said reactorsfor adjustment thereof. A v

ldhen a receiving set having a cable, or

. cord-connected reactor-control has been in use for an extended period,however, the cable stretches to a greater or less degree, thusintroducing undesirable baclrllash and rendering'the tuning operationincreasingly di'icult. "@ne object of my invention, ac cordingly, is toprovide a `cable-connested controly device for a tuning reactor whereinlt has also, to a large extent, been customary to either provide theindicating' dials with permanent Wave-length or frequency* scalemarkings, rendering it necessary to shift the entire dial with respectYto the shaft voi a tuning reactor in the event that the'said scalemarkings do not` properly coincide with a permanent iiduciary mark,carried by the panel, `when the receiver is tuned, successive ly, to aplurality of frequencies. Another object of my invention,therefore, isto proy vide a tuning dial having a movable indicating-scale associatedtherewith, 4vvhich scale may easily be adjusted and tire-d vin theproper position during the manufacture of a radio receiving set. i

According to my invention 1T, provide 'a 31929. Serial No. S'm.,

control device, suitable for use in connection with a variable reactor,comprising a driven element axed to a movable portion of said reactorand a plurality of driving elements carried by an actuating shaft. linterpose a flexible cable, or a cord, between the driving and drivenelements and, further, provide resilient mea-ns, preferably mounted uponthe driven element, forma-intaining the exible connecting device undertension.

of the device, i dispose a discshape element upon the shaft adjacent tothe driven element and provide a spring for holding the scale around,and firmly against, the periphery of the disc-shape element. The movablescale-mounting is capable of numerous modiiications, several of whichwill, hereinafter, be described in detail,

The novel Vfeatures that consider cliarf acteristic of my invention areset forth vvitli particularityin the appended claims. The inventionitself, however, both as toits or- Y ganization'and its method ofoperation, to-

gether vvith'additional objects and advantages thereof?, will best beunderstood' from the following description of a specificembodiment,'when read in connection with the accompanying drawings, inWhich: A Figure l is a perspective view of a gangcondenser comprising apreferred embodi nient of my invention, i j

Fig. 2 is a fragmentary vievv of a control device comprising analternative embodiment of my invention,

lig. 3 is an end elevational view of the device illustrated in Fig. 1,certain non-essential details being omitted,

Fig. d is a detail view of a svviveled lamp mounting,

Fig. 5 is an end elevational view of the device illustrated in Fig. 4,and

Fig. 6 is a fragmentary view of a portion of the device shown in Fig. 1,illustrating the manner in which one end of :a scale may be adjustablyanchored.

The apparatuslillustrated in Figs. 1 and 3 comprises a garlg condenserof the type shown and described in the copending application of Henry C.Forbes, Serial No. 198,153, filed June 11, 1927, and assigned to theWestinghouse Electric & Manufacturing Company.

The condenser comprises a one-piece metallic structure 1 which is shapedsomewhat like a bath tub, having end portions 2 and 3, side portions 4and a bottom portion 5. The side portions 4 are each cutawayintermediate the ends to below the level of the tops of the said ends,leaving a plurality of up-standing ears 6.

Insulating strips 7 are aflixed, by means of rivets 8, to theup-standing ears 6 land to the end portions 2 and 3 and extend parallelto the long axis of the structure.

A plurality of groups of stator assemblies 10 are suspended between, andsupported by, the insulating strips 7 by means of a plurality of smallbolts 11 or analogous devices.

Each end portion of the frame is provided with an opening through whichextends a shaft 12 carrying a plurality of groups 13 of rotor plates.

Additional details of the condenser structure are well known to thoseskilled vin the art, the device being essentially that which wasembodied in the hereinbefore referred to radio receiving set, Radiola17, and, since they form no part of my invention, the said details neednot be more specifically enumerated at this point.

A depending plate 14 is affixed to one end of the metallic structure 1.The plate is provided with a plurality of outstanding ears 15 havingbearing openings through which r extends an operating shaft 16and anidlershaft 17. An actuating knob 18 is aiiixed to one end of theoperating shaft and, normally, is disposed exteriorly of the front panelof a cabinet housing the condenser.

The shaft carries a plurality of small pulleys 19 and 20, to which the'ends of a cable 21, ora similar flexible connecting device, areattached. The cable is wrapped a plurality of times around each of thesmall pulleys, in opposite directions, and the intermediate portionthereof is also wrapped a plurality of times around the periphery of agrooved cupslipe element 22 that is aliixed to the end of therotor-shaft 12 immediately above, and adjacent to, the depending plate14.

An idler pulley 23 is rotatably carried by the idler-shaft 17 and issodisposed with respect to the driving pulley 19 that the cable is guidedinto proper position on the periphery of the cup-shape element.

In order to prevent the cable from slipping on the surface of thecup-shape element, it passes around a snubbing post 24, affixed to theinterior of the saidelement, and beneath aportion 25 of the rim of theelement defined by bending minor peripheral portions 26 thereofinwardly.

A resilient tensioning device 27 is mounted interiorly of the cup-shapeelement, one end of the tension device being so disposed as to contactthe cable after it leaves the snubbing post, and thereby, to exert aconstant tension upon it.

The specific form of the resilient tension device is not an essentialelement of my invention, it being obviously replaceable by a helicalspring or the like.

By reason of the fact .thatthe snubbingpost 24 is interposed between thetension device 27 and the end of the cable which is atlixed to thepulley 18,` forces originating in the said pulley are prevented fromdirectly reaching the said tension device. The effect, therefore, of thetension device, upon the cable, is very gradual. Should the cableelongate, somewhat, during the operation of the control-device, theelongation will/be slowly taken up by the tension spring, but nosubstantial additional force will be placed upon the said spring byreason of the operation of the adjusting shaft. It will thus be seenthat back-lash is prevented throughout the entire useful life of acontrol device comprising my invention. s j

A sectored disc-shape element 29 is mounted on the shaft 12, between thecup-shaped element 22 and the depending plate 14, the said disc-shapeelement vbeing rovided with a plurality of peripheral lprojections 30.One end of a translucent scale 31 is adjustably anchored, as shown inFig. 6, to one of a plurality of ears 32 which extend outwardly from thedisc-shape element. The scale is provided with a plurality of openings33, each of the openings subtending an angle somewhat greater than theangle subtended by each of the peripheral projections 31 on thedisc-shape element and being spaced along the length of the scale tocorrespond to the spacing of the said projections.

The scale is resiliently held in intimate contact with the periphery ofthe disc-shape element/29 by means ofa spring- 34, one end of saidspring being anchored between one of the ears 32 and the cup-shapeelement 22, and the other end of which extends through anl opening inthe end of said scale. By slightly loosening a screw 35, shown in Fig.6, comprised in the anchoring device, the scale may, therefore, be movedcircumferentially of the discshape element a slight amount, in eitherdirection, during the process of manufacture.

End stops, (ngt shown) may be provided to prevent the condenser shaftfrom being rotated too far in either direction.

A swive-led lamp-mounting device 40 is disposed adjacent to thetranslucent scale. The lamp-mounting device, which is shown in detail inFigs. 4 and 5, comprises a socketholding portion 4l extending at rightangles to a base portion 42. The base portion is embossed to providev acircular offset bearing surface 43, which surface is maintained tightlyagainst the rear face of the panel by' means of'a mounting-screw 40 orthe like. 'Ihe swivel-connection of the socket is such as to permit itto be moved out of cooperative relation with the translucent scale forthe kpurpose of insertion or removal of a small lamp 45.

It is not absolutely necessary that one end of the translucent scale beanchored, an alternative form of the scale-holding means being shown inFig. 2. Referring specifically to the latter figure, each end of thescale is pro'- vided with an opening into which the ends of the helicalspring are inserted. The scale, therefore, in the alternative form, istightly held against the periphery of the disc-shape element but isprevented from accidental movement with respect thereto solely byfriction.

Although I have shown, in Fig. 1, a small transformer 51 for energizingthe lamp, any convenient power-source may be utilized for this purpose.

It will, accordingly, be apparent that I have provided an improvedcontrol device for the variable reactors comprised in radio receivingapparatus, wherein back-lash between the driving and driven portions ising variations.

entirely eliminated. My control device isv also advantageous in that theindicatin scale may be shifted at any time, either uring the process ofmanufacture or subsequentthereto, in order to compensate manufacturalsoa valing means between said members, means carried by said driven memberfor keeping said exible means under tension and additional means carriedby said driven member for preventing forces arising in said driving' 70means from directly reaching said tension means.

3. A control device comprisin a driving" member, `a driven member, ilexi'le connecting means between said members, resilient means carried byone of said members for keeping said flexible means 'under tension andsnubbing means carried by one of said members for preventing forcesarising in said driving member from directly reaching said tensionmeans.

4. A control device com rising a driving member, a driven member, exibleconnecting means between said members, resilient means carried by one ofsaid" members and contacting said iiexible means to maintain it undertension and additional means carried by said member for preventingforces arising in said driving member from directly reaching saidtension means.

In testimony whereof, I have hereunto subscribed my name this eighteenthday of June, 1929. r

J OHIN KERRIGAN.

1. A control device comprising a driving member, a driven member,iiexible connecting means betweensaid members, means for keeping saidflexible means under` tension and.means for preventing` forces arisingin said driving means from directly reaching said tension means.

2. Acontrol device comprising a driving f member, a driven member,flexible connect-

